1. Field of the Invention
This invention generally relates to a bicycle front derailleur. More specifically, the present invention relates to an auxiliary bicycle shifting component that can be mounted on a chain guide of a front derailleur.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle drive train.
Bicycles, and particularly sport type bicycles, use chain driven types of drive trains with a front transmission device including a front derailleur and front chain wheel with two or three sprockets, and a rear transmission device including a rear derailleur and multi-stage gears with seven to ten sprockets. The front derailleur of this type of shifting device basically includes a base member, a chain guide and a movement mechanism. The base member is secured to the frame of the bicycle with the chain guide be movable in relation to the base member by the movement mechanism. The chain guide has an inner plate, and an outer plate that is disposed at an interval from the inner plate. The chain guide moves to selectively contact the chain with one of the inner and outer plates. In particular, the chain runs through the space between the inner plate and the outer plate, and the chain guide is moved towards and away from the frame to guide the chain to the desired sprocket. Conventionally known examples of such front derailleurs include those in which the part of the inner side surface of the outer plate of the chain guide on the chain-entry side is depressed farther in than the other portions to allow for smoother downshifting, and to ensure that the chain does not come into contact with the outer plate of the chain guide while the gears are not being shifted (see, for example, U.S. Pat. No. 6,641,494).
If the chain-entry side of the outer plate of the chain guide is depressed farther in than other portions, then the chain will not come into contact with the outer plate while the gears are not being shifted. However, in the case of a rear-suspension bicycle, referred to as a full-suspension bike, the chain is sometimes located on the depressed portion of the chain-entry side when the rear suspension is extended; i.e., when the distal end of the rear frame swings downward in relation to the front frame. When at attempt is made to downshift the gears in this state, sometimes the outer plate cannot efficiently apply pressure to downshift the chain, and the downshifting capability is reduced.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved auxiliary bicycle shifting component. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.